Chapter 4 Information Technology Planning
Dec 26, 2015
Chapter 4
Information Technology Planning
Introduction
• Strategy establishes the broad course of action for the firm– Establishes the destination and the general
direction, but not the details
• Planning encompasses the specific information to reach goals and accomplish objectives– These are the individual specific steps
needed to reach the objective
Assignment #2 - Due June 24th
• Discuss the IT Management Planning Model from Table 4.1 on page 100. Briefly discuss each of the ingredients, and select 1 ingredient and illustrate its importance by way of real world application.
The Planning Horizon
• There are three general types of plans– Strategic Plans – 5 yr– Tactical Plans – 2 yr– Operational Plans and Controls - < 1 yr
• They are distinguished by their time span or planning horizon– The planning horizons of each type of plan
added together equals the firm’s extended planning horizon
Strategic Plans
• Attempt to convert strategies into plans– Take information found in the strategy
statement and add detailed actions and resources necessary to attain the stated goal
– They must convert assumptions in the strategy into reality
– They must mitigate known risks to the fullest extent possible
Tactical Plans
• Intermediate range plans covering the current year in detail and the following in less detail– These plans are used to help assess a
manager’s performance– They link near-term actions and long range
goals
Operational Plans
• Broad based and very detailed– Attempt to deal with important activities
occurring in the near-term– Attempt to bridge the gap from the present to
the tactical time period– Contain detailed information used in the lower
levels in an organization– Provide a basis for taking short-term action
and measuring short-term results
The Extended Planning Horizon
Planning Schedules
• Planning is a continual process, tied to the calendar
• In organizations with well-established planning processes, the new tactical plan revises the second year of the previous plan and adds to it the first year of the previous strategic plan
• Revisions reflect changes due to changes in the business environment
Rapid-Response Planning for Internet Applications
• The leverage businesses obtain with Internet technologies are maximized when they are deployed quickly– In this climate, detailed plans quickly become
dated– Wise managers respond to these changes
quickly, with planning keeping up with the current business environment, rather than slavishly being tied to a calendar
Seven Considerations of IT Planning
1. Application Considerations
• An applications portfolio consists of a complete set of application programs a firm uses to conduct its automated business functions
• Major difficulties surround project selection for the applications portfolio– Arise from competition for resources– Generally resolution requires intervention of
senior executives
2. System Operations
• Running the firm’s applications according to defined processes– Processes may include online ERP systems,
network e-commerce systems, scheduling systems, or a combination
• IT managers must plan system operations and service levels to satisfy customers both within and outside the firm
3. Resource Planning
• IT resources consist of equipment, space, people, and finances– The IT plan describes the critical
dependencies on available resources throughout the planning horizon
– The plan must encompass all necessary obligations and expenses including leasing and finance costs, third party services, and capital equipment expenditures
4. People Plans
• The most crucial element of any plan– People management is a necessary condition
for success but not sufficient by itself– Planning includes staffing, training and
retraining costs, and time– The personnel plan identifies requirements for
people according to skill level– At the level of line management, this includes
formulation of individual development plans for employees
5. Financial Plans
• For an IT organization, this summarizes the costs of equipment, space, people, and miscellaneous items– Timing of expenditures reflect the rate at
which the firm acquires or expends resources consistent with work product
– Planning is iterative, with the figures changing due to negotiations and discussions
– An IT manager’s performance is often judged against the financial plan
6. Administrative Actions
• The cooperation of managers in adjacent functions must occur to help coordinate the emerging plan– Bringing others in helps develop win-win
strategies among the participants– Open lines of communication help to integrate
participants across departments– Measurement and tracking mechanisms must
be developed to monitor progress and help management assert control
7. Technology Planning
• The IT organization must stay informed about progress in the field– The rate of change in IT is enormous, with
many enormous advances and technologic dead ends
– In larger organizations, a small advanced technology group is useful to better quantify new technologies and their applicability to the current environment
Technology Areas
The Integrated Approach
• Some planning strategies are more suited to certain situations than others
• Two factors correlate with planning effectiveness– Infusion – the degree to which IT has
penetrated the operation of the firm– Diffusion – the extent to which IT has
disseminated throughout the firm
Critical Success Factors in Planning
• CSFs are critical tools in creating effective plans– Improve planning by focusing on important
managerial issues– Audit the results of the planning process
• Four major categories– Long, intermediate, and short range issues– Business management issues
Business Systems Planning
• Concentrates on a firm’s data resources and attempts to develop an information architecture that supports a coordinated view of the data needs of the firm’s major systems
• Attempts to model the firm’s business through its information resources– Attention is shifted from the firm’s applications
to the firm’s data
Forecast-Based
• Forecast or extrapolation strategies work in firms in which the technology is limited in terms of its use, and does not have a high impact– These firms tend to use older generations of
equipment in very circumscribed roles– Rapid advances in the state of the art can be
ignored and as a late or limited adopter, risks and benefits can be well quantified
Eclectic Planning Strategies
• Technological approach– Attempts to build an IS-oriented architecture
• Administrative approach– Bottom-up resource allocation
• Method-Driven approach– Use consultants to critique existing plans
• Business-led– Assumes business plans will lead to IT plans
Management Feedback Mechanisms
• Control consists of knowing who, what, why, where, and when for all essential activities
• Control processes must be designed to compare the organization’s actual performance to plan predicted performance
Summary
• Sound planning is critical for success• Planning is divided into time periods of
differing lengths• Plans are only as good as their
implementation and control mechanisms• Control is a fundamental management
responsibility• Measurements are key to gauging planning
success and deviation
Chapter 5
Hardware and Software Trends
Introduction
• Four key areas have fueled the advances in telecommunications and computing– Semiconductor fabrication– Magnetic recording– Networking and communications systems– Software development
Exponential Growth
• Gordon Moore (a founder of Intel) observed a trend in semiconductor growth in 1965 that has held firm for close to 40 years
• Moore’s Law states that the number of transistors on an integrated circuit doubles every 18 months
• Similar performance curves exist in the telecommunication and magnetic recording industries
Semiconductor Technology
• The transistor was invented at Bell Labs in 1947 by John Bardeen, Walter Brattain, and William Shockley
• Semiconductors form the foundation upon which much of the modern information industry is based
• Advances in process have allowed system designers to pack more performance into more devices at decreased cost
Trends in Semiconductor Technology
1. Diminishing device size
2. Increasing density of devices on chips
3. Faster switching speeds
4. Expanded function per chip
5. Increased reliability
6. Rapidly declining unit cost
Semiconductor Performance
• As device size shrinks, performance improves and capability increases (more logic elements in the same size package and those elements operate faster)
• During the period from 1960 to 1990 density grew by 7 orders of magnitude– 3 circuits to 3 million– By 2020, chips will hold between 1 to 10
billion circuits
Roadblocks to Device Shrinkage
• As the minimum feature size decreases, components are closer together and the number of components per unit area increases
• Both these factors increase the amount of waste heat needed to be removed from a device
• Effectively removing this heat is a big challenge
Industry Success
• Success of the semiconductor industry is driven by huge budgets for scientific research, process design, and innovation
• Since the semiconductor was invented, the industry has experienced a growth rate of 100 times per decade
Industry Innovation
• Increases in device processing power comes not only from increased clock rates and decreased device sizes
• Innovation in physical computer architecture also drives performance– Bus widths have increased from 8 to 16 to 32
and now are growing to 64-bit wide– With wider busses, more data can be
transferred from place to place on the chip simultaneously, increasing performance
Industry Innovation
• Cache Memory – Fast, high speed memory used to buffer program data near the processor to avoid data access delays
• Super scalar designs – designs that allow more than one instruction to be executed at a time
• Hyperthreading – adding a small amount of extra on-chip hardware that allows one processor to efficiently act as two, boosting performance by 25 %
Semiconductor Content
• Microprocessors comprise less than 50% of total chip production
• Memory, application-specific integrated circuits (ASICs), and custom silicon make up the bulk of production
• The telecommunications industry is a huge driver worldwide as cell phone penetration increases
Summary
• The invention and innovation of the semiconductor industry has been enormously important
• Chip densities will continue to increase due to innovation in physics, metallurgy, chemistry, and manufacturing tools and processes
• Semiconductors will continue to be cheaper, faster, and more capable
Recording Technologies
• As dramatic as the progress in semiconductor development is, progress in recording technologies is even more rapid
• Disk-based magnetic storage grew at a compounded rate of 25% through the 1980s but then accelerated to 60% in the early 1990s and further increased to in excess of 100% by the turn of the century
Exploding Demand
• As personal computers have grown in computing power, storage demands have also accelerated– Operating systems and common application
suites consume several gigabytes of storage to start with
– The World Wide Web requires vast amounts of online storage of information
– Disk storage is being integrated into consumer electronics
Recording Economics
• At current rates of growth, disk capacities are doubling every six months
• Growth rates are exceeding Moore’s Law kinetics by a factor of three
• Price per megabyte has declined from 4 cents in 1998 to 0.07 cent in 2002
Hard Drive Anatomy
• Data is stored on hard drives in concentric circles called “Tracks”
• Each track is divided into segments called “Sectors”
• A drive may contain multiple disks called “Platters”
• Writing or reading data is done by small recording heads supported by a mobile arm
Hard Drive Performance
• Drive performance is commonly measured by how quickly data can be retrieved and written
• Two common measures are used– Seek Time– Rotational Delay
Hard Drive Performance
• Seek Time is the amount of time it takes the heads to move from one track to another– This time is commonly measured in
milliseconds (ms or thousandths of a second)– For a processor operating at 1 Ghz, 1 ms is
enough time to execute one million instructions– Common seek times of inexpensive drives are
from 7 to 9 ms
Rotational Delay
• The delay imposed by waiting for the correct sector of data to move under the read / write heads– Current drives spin at 7200 RPM.– Faster rotational speeds decrease rotational
delay• High end server drives spin at 15000 RPM, with
surface speeds exceeding 100 MPH• Heads float on a cushion of air 3 millionths of an
inch thick
Other Performance Issues
• Data transfer interfaces are constantly evolving to keep pace with higher drive performance.
• New standards include:– Firewire– USB 2– InfiniBand
Fault-Tolerant Storage
• Data has become a strategic asset of most businesses
• Loss of data can cripple and sometimes kill an enterprise
• Fault-tolerant storage systems have become more important as data availability has become more critical
RAID Storage
• RAID is an acronym that stands for Redundant Array of Inexpensive Drives
• RAIDs spread data across multiple drives to reduce the chance that the failure of one drive would result in data loss
• RAID levels commonly range from 0 to 5 with some derivative cases
CD-ROM Storage
• Five inches in diameter, capable of holding 650 MB of data
• So inexpensive, powerful, and widespread are these disks, that many PC manufacturers are discontinuing the sale of 1.44 MB floppy drives in new PCs
• CD-R blanks are now costing approximately 5 cents each
DVD Storage
• DVDs or Digital Versatile Discs
• Store 4.7 GB of digital data
• Can be used to store video, audio, or larger data archives
Computer Architecture
• Computers include:– Memory– Mass storage– Logic– Peripherals– Input devices– Displays
Supercomputers
• At the extreme edge of the computing spectrum, supercomputers are clusters of individual machines lashed together with high-speed network connections
• The 50 most powerful supercomputers in existence today are built of no less than 64 processors
• The most powerful are composed of close to 10,000 individual processors
Microcomputers
• The first microcomputer was sold by IBM in the early 1970s
• With the progress of Moore's Law, PCs have become more and more powerful with desktop systems able to deliver in excess of 2500 MIPS (millions of instructions per second)
• 10000 MIPS systems will be commonplace by the end of the decade
Trends in Systems Architecture
• Slowly systems are shifting from being PC focused to network focused
Client/Server Computing
• With powerful graphical workstations and high-speed networking, PCs have become the user interface engine, not the application
• The most obvious example is the Web browser. Any number of servers using numerous different server programs are all accessible by the same Web client
Thin Clients
• With the “hollowing out of the computer”, client PCs no longer need to “do it all”
• Called “thin” because they have minimal local storage, and function primarily as display devices
• Applications are executed locally but reside remotely
Benefits of Thin Clients
• Thin clients allow businesses to have a high degree of control over user’s desktops
• Central client management eases troubleshooting and allows rollout of application upgrades without much overhead
• Thin clients commonly lack removable storage so data security is enhanced
Communications Technology
• The same semiconductor and switching technologies that have driven the computer revolution have driven the telecommunications revolution
• Fiber-optic data capacity has increased even faster than Moore’s Law rates for semiconductors
• Fiber-optic capacity doubles every six months
Intranets, Extranets, and the WWW
• Intranet – Network dedicated to internal corporate use
• Extranet – Network used to bring partners external to the company into the corporate network
The World Wide Web
• Invented by Tim Berners-Lee at CERN
• Open standard client/server interface
• Uses open standard HTML for page formatting and display
• The Web creates a powerful open access structure that everyone can leverage for business needs
WWW and Business
• Intranets, extranets, and the Internet all play parts in creating an e-enabled business
• Client/server architectures modularize components allowing special purpose or custom built systems for online business
Operating Systems
• Current examples are– Microsoft Windows XP– Linux (Open source)– Apple OS X– Free BSD (Open source)– Solaris (Sun)– AIX (IBM)
History of Operating Systems
• First programs were called “Monitors”– They allowed operators to more easily load
programs and retrieve output
• Uniprocessing – executing one program at a time
• Multiprocessing – appearing to execute several programs simultaneously by processing a few instructions from each in succession
Network Operating Systems
• Operating systems that incorporate network aware hooks so that systems can utilize resources seamlessly across the network infrastructure
• Microsoft’s Windows 2000 and Linux both incorporate these elements directly out of the box
Application Programming
• Internet technology requires new tools to exploit its full potential– Markup languages such as SGML, HTML,
and XML– Java is used to code applications that can run
on a broad range of operating systems and microprocessors
Recapitulation
• The torrent of innovation of the past 30 years will continue
• Technology will open opportunities and foster innovation that will continue to change our way of life
• It is as important how we use technology as it is what technology enables. These innovations are tools, and carry the same moral hazards that all tools have
Implications
• Tomorrow’s managers will have magnitudes greater capability than today’s
• Huge data stores will profile customers, patients, and employees
• Intranets will begin to break down the barriers between levels of management, eliminating distance in time and bureaucracy
Implications
• Business models are changing with B2B, B2C, and ASP models becoming rapidly growing markets
• Information is a strategic asset as well as a business tool
• With rapid, granular Internet information strategies, information may be shared even with competitors if it serves a business purpose at the time
Summary
• New breakthroughs in information processing technology will challenge our ability to harness and integrate these advances into society, corporations, and governmental organizations
• Rapid organizational changes will be the norm
• Failure to embrace change dooms organizations and their leaders to failure
Chapter 6
Modern Telecommunications Systems
Telecommunications
• The science and technology of communication by electronic transmission of impulses through telegraphy, cable, telephony, radio, or television either with or without physical media
• Tele is Greek for distance
• Communicate has its roots in the Latin word “to impart”
Voice Networks
• Interactive - Bidirectional networks that provide on-demand communication
• The first telephone networks were deployed widely following World War II
• By the late 1950s in the United States, telephones were a permanent fixture in most homes
Circuit Switched Networks
• Telephone networks use circuit switching that creates a complete, dedicated, end to end connection before voice data begins to flow
• Circuit creation results in exclusive allocation of specific data transmission resources for the duration of the call
Circuit Switching
• Guarantees that each successful connection owns all the resources necessary to deliver a high quality link
• When the call ends, the circuit is torn down, and the resources are freed; these resources can then be utilized for a new connection
Legacy
• The telephone network is one of the largest legacy systems ever created and maintained
• Phone handsets over 50 years old can still interoperate seamlessly with current equipment
• Some basic design specifications date back to the early 1900s
Telephone Signals
• Original telephone specifications were based on analog signal technology
• Analog signals vary in amplitude (signal strength) and in frequency (pitch)
• The telephone handset converts sound into continuously varying electrical signals with the microphone
• The speaker at the other end converts electrical signals back to sound
Analog Signal
Digital Signals
• These signals are discrete and discontinuous
• They exist in predetermined states
• Binary signals are digital signals limited to only two states, 0 and 1
Digital Signal
Multiplexing
• Multiplexing is subdividing the physical media into two or more channels
• Telephone lines use frequency multiplexing to carry both voice and DSL signals simultaneously
• The frequencies between 0 and 4000 Hz carry voice, and those between 25 kHz and 1.5 MHz carry DSL
Digitizing Voice Signals
• By converting analog voice signals into a digital format, voice can then be processed like other digital data by computers
• The economies of Moore’s law and semiconductor economics can be brought to bear on voice applications
Pulse Amplitude and Pulse Code Modification
Analog to Digital Conversion
• Generally a two step process– First, the analog signal is sampled at regular
intervals; measurements taken at these periods are converted to a discrete value
– Second, the discrete values are converted to a binary format; this is called pulse code modulation
Fidelity
• Translating a signal from analog to digital format results in loss of data. By increasing the number of discrete values produced per second (sampling more often) and increasing the range of discrete values produced by sampling, the digitized waveform more closely represents the analog original. This is fidelity.
Topology
• Topology is the configuration of elements in a network
• The local exchange (local switch and all attached CPE and trunks) form a switched star network
• This is an effective arrangement when most of the lines are idle at any one time
• At peak hours 15% of a given set of lines are in use
T-Services
• T-services are high speed digital links using time-division multiplexing (TDM) to move multiple signals
• TDM successively allocates time segments on a transmission medium to different users
• It combines multiple low speed streams into one high speed stream
T-1
• The T-1 line is capable of carrying 1.544 Mbps
• The T-1 frame is composed of 24 time slices. Each time slice is a channel. Each channel is capable of carrying one phone circuit.
Time-Division Multiplexing and the T-1 Frame
T-1 Frame
• Multiplexing equipment aggregates the incoming individual channels and constructs a frame
• Each channel can transmit 8 bits per frame• Each frame contains 24 channels and one
“framing” or start bit• 8000 frames are transmitted per second
yielding 1.544 Mbps
The T-Service Hierarchy
• The T-1 connection is composed of 24 channels called B channels
• They are able to carry the digitized audio data for one voice circuit
• A T-1 connection can carry 24 Bs
• A T-3 connection can carry 672 Bs (45 Mbps)
T-Services
E-Services
• Europeans use a slightly different standard called the E series
• 8000 frames per second with each frame composed of 32 channels
• Only 30 of the channels can be used for data, the other two are reserved for signaling information and signaling the framing start sequence
• Carries 2.048 Mbps
Data Communication Networks
• Voice networks have hard requirements for network latency (the amount of time needed for data to move from one end to the other)
• Data that arrives late or out of order is worthless
• Pure data networks have looser time constraints opening the door to different topologies and technologies
Packet Switching
• In traditional voice networks, circuits are established that provide for a continuous stream of data; packet switching takes outgoing data and aggregates it into segments called packets
• Packets carry up to 1500 bytes at a time
• Packets have a header prepended onto the front of the packet that contains the destination address and sequence number
Packet Routing
• In circuit switched networks, the entire data pathway is created before data transmission commences; in packet networks, the packet travels from router to router across the network
• At each router, the next hop is chosen, slowly advancing the packet toward its destination
Packet Routing
• Given moment to moment changes in network loading and connections, packets may or may not take the same route
• In taking different routes, packets may arrive in a different order than the order they were transmitted
• The destination uses the sequence number in the header to reassemble the incoming data in the correct order
Local Area Networking
• Until the 1990s, local area networking used vendor specific protocols that made interoperability difficult
• With widespread deployment of personal computers, networking to the desktop became more imperative for companies, so that they could fully leverage their IT infrastructure investments
Metcalfe’s Law
• Robert Metcalfe is the patent holder for Ethernet networking
• He asserted that the value of a network increases as a square function to the number of attached nodes
OSI Model
• OSI was the Open System Interconnection model that attempted to modularize and compartmentalize networking interfaces
• The result was a seven layer model• As data passes down from layer 7 to layer 1 it
is broken into smaller pieces and encapsulated with wrappers of additional information used at the corresponding layer by the recipient to reconstruct the original data and destination
Open System Interconnection Model
OSI is a Model
• OSI was intended to be the final structure and framework for global networking
• Widespread implementation of the entire OSI model has never taken place– It took years to develop– It was the product of a committee– It was extremely rigid
ARPANET
• In the early 1970s, the Department of Defense saw the need to make heterogeneous networks of information systems communicate seamlessly
• They needed networks that were self healing and had a distributed intelligence
• ARPA (Advanced Research Projects Agency) took the OSI layering concept and built an operational system with layers 3, 4, and 5 only
The Internet
• From this nucleus of networked machines grew the Internet
• ARPA called the OSI layer 4 protocol TCP (Transmission Control Protocol) and layer 3 IP (Internet Protocol), hence the Internet networking standard TCP/IP
• This has become the de facto global standard, and OSI has been relegated to a reference model
Internetworking Technology
• The Internet Protocol Suite is a group of helper applications that standardizes interactions between systems and assists users in navigating the Internet
• These helper applications work at many different levels of the OSI model from seven all the way down to two
Internet Protocol Suite
• Layer seven applications include– FTP – File Transfer Protocol– HTTP – HyperText Transfer Protocol– SMTP – Simple Mail Transfer Protocol
• Layer two protocols include– ARP – Address Resolution Protocol
Internet Protocol
• The Layer three protocol is responsible for the standard dotted decimal notation used for computer addressing– Each machine has a unique address specified
by a set of four numbers ranging from 0 to 255
– These numbers are separated by decimal points in the format 216.39.202.114
DNS
• Domain Name System– A distributed database that contains the
mappings between IP numbers and human readable naming
– DNS is also a Internet Protocol Suite helper application
– DNS takes a request for www.yahoo.com and returns the corresponding IP address
Domain Names
• Composed of a hierarchical naming database
• Moves from general to specific in a right to left manner
• The rightmost element of the name is called the Top Level Domain (TLD)
• TLDs can be country codes, organizations (.org), commercial (.com), and others
Communication Between Networks
• Layers 1 and 2 are used for the transmission of data packets between routers
• Layer 1 – The Physical Layer– Specifies voltage parameters, timing signaling
rates, and cable specifications
• Layer 2 – The Data Link Layer– Describes how data is formatted for transmission
across a specific type of Physical Layer link
Physical Layer Technologies
• Transmission links can be built using either conducting or radiating media– Conducting media create a direct physical
connection between network components like copper wire or fiber optics
– Radiating media uses radio waves to link stations together
10 Base T
• The most common Ethernet based wiring standard
• Uses 8 stranded wire links• These wires are similar in size to telephone
wire and use slightly larger modular plugs• Carries data signals at 10 Mbps to 1000
Mbps over distances up to several hundred meters
Coaxial Cable
• Useful to carry signals over distances up to several miles
• Diameter of coax ranges from 1/4th inch to one inch
• Inner wire surrounded by a foam insulator, wrapped by a metal shield and covered with an external insulator
Coaxial Cable Construction
Optical-Fiber Media
• Used in new installations instead of coax
• Capable of carrying extremely high rates of data over distances exceeding 100 miles
• Constructed of a glass core covered with plastic cladding and bundled with a tough external sheath
Advanced Fiber Transport
• Due to low installation costs and high data capacity, optical fiber is the medium of choice for new buildings
• Fiber has the flexibility to carry voice, data, and video with no change to the installed fiber base
The Last Mile
• High speed global networks are of little value if individual access is unavailable
• WANs terminate locally at POPs (Points of Presence)
• For businesses, T-1 connections are a common solution to the last mile; T-1s are expensive to setup and require long term contracts
Digital Subscriber Lines
• DSL enables regional phone providers to deliver digital connectivity to customers over existing copper connections
• At the local switch, an additional network unit is installed called a DSLAM (Digital Subscriber Local Access Multiplexer)
• The DSLAM injects and extracts the DSL information into the copper line
DSL
• On the customer side, a modem/router is attached to the line, injecting and extracting the DSL signals
• DSL connections from the customer to the local switch is limited to 3.5 miles
• 80% of phone subscribers in the US are currently within these boundaries
Digital Cable
• 60% of US homes and businesses are accessible to cable broadcasters
• Cable initially was designed for one way content delivery
• In the 1990s, systems were upgraded to deliver interactive programming and digital data access
Digital Cable
• The highest margin, fastest growth sector of the cable industry is cable-based Internet access
• Cable providers piggyback a 5 – 10 Mbps digital backbone onto existing broadcast spectrum
• Home users attach specially constructed “Cable Modems” (routers) to interface home systems to the cable data feed
Voice Over Cable
• Cable operators want to bundle more services for customers
• Delivery of telephone connectivity over cable systems is an additional service they can provide
• This service will require additional capital outlays to provision customers at a time when “growth at any cost” is not a viable business strategy
Wireless Systems
• Licensed wireless – Includes cellular voice and data networks
• Unlicensed wireless – ad hoc networking technologies like 802.11b and 802.11g
• Both these technologies enable consumers to have untethered, mobile connectivity bringing networking to the consumer instead of making the consumer find the network
Licensed Wireless
• Cellular service first began in the early 1980s
• It has grown at a 30% compounded rate over the last decade with penetration of 50% across the US
• Cellular systems are dense networks of low power broadband radio transmitters and receivers
Cellular Network Architecture
Unlicensed Wireless
• 802.11.b – An Ethernet networking standard that replaces layers 1 and 2 with a wireless equivalent
• 11 Mbps network connectivity over a 50m radius
• No transmitter license is necessary so it is inexpensive for consumers with little setup or administration costs